Ophthalmic lens for the compensation of eyesight defects are well known. One of the main problems encountered in the field of ophthalmic correction is the correction of the condition presbyopia where the eye exhibits a progressively diminished ability with age to focus on near objects. Typically the condition is addressed by the use of bifocal or multifocal contact lenses that attempt to correct both near and far vision with the same lenses, the lens having a far vision region and a near vision region. Progressive ophthalmic lenses usually comprise a far vision region, a near vision region, and a progressive corridor (or channel) there between. The progressive corridor provides a gradual power progression from the far vision zone to the near vision zone without a dividing line or a prismatic jump.
While the use of such lenses can help to provide a net vision at a range of distances they can also lead to artifacts, such as distortion, spatial restrictions problems of adaptation which complicate the design, manufacture and the use of such lenses. Unifocal lenses on the other hand do not lead to such defects by only enable one range of good quality vision to be provided.
Traditionally prescribing ophthalmic lens to a wearer involves fitting a potential wearer having an eyesight defect with ophthalmic lenses having different optical characteristics and then selecting the lenses which provide the best optical performance for the wearer. Such techniques suffer the drawback that the wearer has to go through the process of putting off and taking off a number of spectacles and may only be exposed to a limited selection of lenses which may not include the optical lens optimal for correcting the particular eyesight defect.
US 2004/0156021 discloses an ophthalmic lens arrangement according to the prior art. Such prior art arrangement suffers a number of drawbacks such as the limitation in of the size of the optical lens, the limitation in the amplitude of optical power variation, the limitation in the chromatic aberration and the arising of high order diffraction modes.